DSP: add Ringbuffer, Delay101, Delta

src/utils.hh

@@ -10,7 +10,7 @@ namespace Heck::OSP {
 
     float scalen_min_max(float val, float min, float max);
     float scalen_center_range(float val, float center, float range);
-} // namespace Heck
+} // namespace Heck::OSP
 
 
 namespace Heck::OSP {
@@ -27,7 +27,7 @@ namespace Heck::OSP {
         u32 time_last_exec_{};
         u32 time_period_{};
     };
-} // namespace Heck
+} // namespace Heck::OSP
 
 namespace Heck::OSP {
     template<typename T> class Observer {
@@ -56,5 +56,77 @@ namespace Heck::OSP {
     private:
         T val_current_{};
     };
-} // namespace Heck
-#endif // HECK_DAISY_UTILS_HH`
+} // namespace Heck::OSP
+
+namespace Heck::OSP {
+    namespace Sig {
+        struct Delta {
+            float process(float in)
+            {
+                float delta = in - history[0];
+                if (abs(delta) < 0.4) {
+                    delta == 0;
+                }
+                history[0] = in;
+                return delta;
+            }
+
+            float history[1];
+        };
+
+        template<u32 SIZE> struct RingBuffer {
+            void init(float* buffer)
+            {
+                buf_ = buffer;
+            }
+
+            void push_front(float in)
+            {
+                u32 index_new = index_first_ + 1;
+                if (index_new < SIZE) {
+                    index_first_ = index_new;
+                } else {
+                    index_first_ = 0;
+                }
+
+                buf_[index_first_] = in;
+            }
+
+            // index 0 reads the last sample written
+            float get(u32 index) const
+            {
+                u32 pos_read = index_first_ + index;
+                if (!(pos_read < SIZE)) {
+                    pos_read = pos_read - (SIZE - 1);
+                }
+                return buf_[pos_read];
+            }
+
+            u32 index_first_{ SIZE - 1 };
+            float* buf_;
+            u32 size = SIZE;
+        };
+
+        template<int SIZE> struct Delay101 {
+            void init(Sig::RingBuffer<SIZE>* buff)
+            {
+                buff_ = buff;
+            }
+
+            float process(float sig_in)
+            {
+                buff_->push_front(sig_in + (sig_tap1_ * delayfb_));
+                sig_tap1_ = buff_->get(buff_->size - (u32)((delaytime_ * delaytime_) * buff_->size));
+                return sig_in + sig_tap1_;
+            }
+
+            float delayfb_;   // 0-1
+            float delaytime_; // 0-1
+            float sig_tap1_;
+            Sig::RingBuffer<SIZE>* buff_;
+        };
+
+
+    } // namespace Sig
+} // namespace Heck::OSP
+#endif // HECK_DAISY_UTILS_HH